CORRELATION OF EXPERIMENTAL-DATA AND 3-DIMENSIONAL FINITE-ELEMENT MODELING OF A SPINNING MAGNET ARRAY

A magnet array was spun above an aluminum disk, and the drag torque wa s measured for various speeds and pp sizes. Drag torques calculated us ing a three-dimensional finite element program were consistent with me asured values. The finite element model was also used to determine the effects of the polarity and position of magnets in the source array. The peak torque was shown to occur when magnets are located at a radiu s equal to 70% of the disk radius. A magnet array with alternate magne ts reversed was shown to produce more than twice the drag of an array comprised of parallel magnets. An approximation for fields under the m agnet centers was obtained using a two-dimensional analytical solution .